Regulate Your Nervous System for Better Sleep and Joy

What if the biggest limit on how well you sleep, perform and show up for the people you love is not willpower or discipline but the quiet control system running beneath your ribs? In a long conversation with Dr Rangan Chatterjee, Dr Kristen Holmes, Global Head of Human Performance and Principal Scientist at WHOOP, makes the case that the autonomic nervous system is the foundation of health, capacity and emotional life, and that it can be trained through a small set of unglamorous daily habits. Her new book, Aligned, joins physiology and psychology in one argument: sleep timing and light exposure on one side, memory, attachment and self-compassion on the other. The episode runs from the biology of the two nervous system branches to the practical question of which health metric to track, and from morning light to the uncomfortable habit of reaching for sugar or a phone screen whenever something hurts.

Who actually controls the autonomic nervous system?

The conversation opens with a provocation Holmes has used before: the world is divided into people who have control of their autonomic nervous system and people who don't. Her answer frames the whole book. Performance and health, she argues, are both constrained by capacity, and capacity is built by a robust autonomic nervous system. The people who thrive are not the ones who never feel stress. They are the ones who can respond in a way that matches who they want to be.

Holmes described her own practice in the first minutes of the episode:

"When I feel that dissonance bubble up, I don't just let it fester. I take some action and I course correct, right? And I bring myself back into a regulated state."

— Kristen Holmes, on Dr Rangan Chatterjee's podcast (about 0:00 to 2:20)

The mechanics she laid out are simple enough to hold in your head. The autonomic nervous system is part of the peripheral nervous system, which sits outside the brain and spinal cord. It has two branches, the sympathetic (the accelerator, mobilising you for action) and the parasympathetic (the brake, restoring calm). Both send competing signals to the heart. The more regulated you are, the more responsive your heart is to the shifting demands placed on it. Holmes used a stark example to make the point: when the heart stops responding to those demands, you are in serious trouble. Less dramatically, a disregulated system leaves you debilitated, unable to respond effectively to external stress.

This is why she describes regulation as the ability to toggle between activation and deactivation with conscious awareness. It is not about eliminating stress. It is about moving through it and back out again.

Why does a dysregulated nervous system look like aging?

Holmes took the idea further than performance. She pointed to a December 2025 opinion piece that examined the leading theories of aging and the hallmarks researchers usually list: telomere attrition, genomic instability, mitochondrial dysfunction and inflammation. Her reading of that piece is that these hallmarks are downstream of a disregulated autonomic nervous system. If that framing holds, the body's slow decline and its acute fatigue share a common root.

Chatterjee pushed the point toward relationships, and Holmes agreed that the stakes go beyond the body. Reactivity with a partner, a child or a colleague, she suggested, is also a product of the same system. Her summary was blunt: a well-regulated nervous system may be the most important thing to focus on, because better health, longevity and performance all flow from it, and so do the quality of our relationships.

The implication is that when someone says they want to be healthier, the first question is not which supplement or diet to add. It is how their nervous system is handling load, and whether they can recover from it at all.

Which daily habits build a more resilient nervous system?

Holmes organises the first half of Aligned around foundations most people have heard before: sleep and circadian alignment, appropriate training, appropriate rest, and a working understanding of stress and recovery. The novelty lies in how she connects them. The episode's description notes that she presents four simple, free behaviours, tested across 39,000 people, that support better sleep and recovery, and that the conversation highlights morning light and consistent sleep and wake times among them.

The circadian thread runs through the discussion. Chatterjee and Holmes spent time on the timing of light and the role of melatonin, the hormone that tells the body it is night. The practical takeaway is that the body reads light as a timing signal, and when that signal arrives at the wrong hour, sleep and recovery pay the price. Morning light and a steady wake time anchor the cycle. A steady bedtime keeps it from drifting.

When the conversation turned to choosing a single metric to track, Holmes engaged with the question seriously, weighing the trade-off between a number that is easy to read and one that reflects what is actually happening underneath. Her answer, and her reasoning, are worth hearing in full from the episode itself.

Why do we soothe discomfort with sugar, alcohol and scrolling?

Chatterjee raised a frustration many listeners will recognise. Health advice keeps repeating the dangers of sugar and alcohol, yet people keep reaching for them. His explanation is that behaviour is often downstream of mindset. If life feels bleak, the body wants relief, and ice cream, a drink or a feed of endless content is the fastest route. Telling someone to stop will not work if the feeling driving the habit is untouched.

Holmes agreed with the logic but moved the emphasis. She said she goes back and forth on whether physiology or psychology is the better entry point, and that there is truth in both. Her sharper point concerns self-perception rather than worldview: "it's not even how we see the world, it's how we see ourselves."

She illustrated this with her own story, which she tells at the opening of Aligned. She described her mother, who harmed herself over the course of her life through heavy drinking. Her verdict on that period: she did not love herself and did not have compassion for herself. For Holmes, that is where change has to begin. Before adjusting the diet, a person needs to work out what loving themselves actually looks like in practice: how the body should be treated, how the mind should be treated.

"When we feel that internal tension, that is usually a direct comment on something that matters to you. Instead of thinking about the thing that matters to us, because it might be a little uncomfortable, we soothe it with food or scrolling. We basically try to mute that signal."

— Kristen Holmes, on Dr Rangan Chatterjee's podcast (about 8:05 to 9:30)

Her call to action is to feel the signal rather than mute it. Get curious about it. Then decide whether the moment requires action or whether you can let it go. She is careful to say the decision itself matters less than the awareness behind it. The conscious pause is the skill. Sugar reduction and walking, she noted, are a kind of parasympathetic fix, a useful tool but not the whole repair.

Can change start from self-compassion rather than self-criticism?

The emotional core of the episode is Holmes's insistence that lasting change begins with understanding yourself rather than criticising yourself. Harsh self-judgement tends to produce the same thing it is trying to cure: more stress, more threat, more reason to soothe. Self-compassion, in her framing, is what lets someone look at the discomfort long enough to learn from it.

Identity is the lever she returns to. Asked what makes change stick, she reached for a broad answer: "I think the secret to life is identity." The work, as she puts it, is figuring out who you want to be and what you need to engage in to become that person. Carving out time and space for those commitments is what turns an abstract value into daily behaviour. Living in line with your values is, for her, the practical meaning of alignment.

The closing stretch of the conversation turns from management to meaning. Chatterjee and Holmes discuss cultivating joy rather than chasing happiness, the distinction between a feeling that comes and goes and a settled sense of peace, and the practice of loving-kindness. Holmes describes a relationship with an open heart as something that can be cultivated deliberately, not only stumbled into. Journaling comes up as one concrete way to start.

Where to go from here

If you take one thread from this conversation, make it the idea that regulation is a skill you can practise. Start with what is free and immediate: get outside in the morning light, keep your wake time steady, and notice the next time you reach for food or a screen to dull a feeling. Ask what the feeling is pointing at. Then decide whether it needs action.

For the full argument, read Aligned, which Holmes wrote to connect physiology with memory, attachment and identity. Listen to the full episode for the detail behind her four behaviours, her thinking on single-metric tracking, and the conversation about holidays and illness that the episode raises. The physiology gives you a starting point. The psychology, she suggests, is where the work actually changes you.